<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>考试界面</title>
  <style>
    #startExamBtn
    {
      padding: 20px 30px;
      background-color: #4CAF50;
      color: white;
      border: none;
      cursor: pointer;
      font-size: 16px;
      width: 200px; 
      margin: 0 auto; 
      overflow: hidden;
      display: grid;
      justify-items: center;
    }
    body {
      font-family: Arial, sans-serif;
    }

 .container {
      width: 80%;
      margin: 0 auto;
    }

 .waiting {
      background-color: lightgray;
      padding: 20px;
      text-align: center;
    }

 .exam {
      background-color: white;
      padding: 20px;
      display: none;
    }

 .finished {
      background-color: lightgreen;
      padding: 20px;
      text-align: center;
      display: none;
    }

 .countdown-panel {
      position: absolute;
      top: 0;
      right: 0;
      background-color: rgba(0, 0, 0, 0.7);
      color: white;
      padding: 10px;
      border-radius: 5px;
    }
 
  </style>
</head>

<body>
  <div class="container">
    <div class="waiting">
      <h2>等待考试开始...</h2>
      <p>考试将在[]开始，请耐心等待。</p>
      <br>
      
      <button id="startExamBtn" onclick="gonext()"  >开始考试</button>
    
    </div>
    <div class="finished">
      <h2>考试结束</h2>
      <p>您已完成考试，感谢您的参与！</p>
    </div>
    <div class="countdown-panel" id="countdownPanel"></div>
  </div>
<script>
function gonext()
{
  window.location.href="ExamPage.html"
}
</script>
  
</body>

</html>